Oil burner



April 2, 1929. I:- A, HEATH 1,707,474

OIL BUNER Filed Aug. 5, 1925 4 SheetsK-Sheet E 'MII A zu lllllll April2, 1929. F; HEATH `1,707,474

' oIL BURNER Filed Aug. 5, 1925l -4 sheets-sheet `4 K fr/'wf AffeazhPatented Apr.. 2, 1929.

UNiTao. srarlaisg PATENT `l.o1-Fica FORREST HEATH,`OF DETROIT, MICHIGAN,ASSIGNOR F ONE-THIRD T0 HIMSELI, ONE-THIRD T0 KARL 1B. SEGALL, ANDONE-THIRD T0 WALTER F. TANT, .ALL 0F DETROIT, MICHIGAN.

OIL BURNER.

`Appiiaitmii ineav August s, 1925. serial no. 47,709.

My present invention is shown in connection with an oil burner of theso-called automatic type adapted to burn liquid fuel, particularly theheavier' or so-called fuel oils,

5 and the construction .of the burner unit peculiarly adapts it -forconverting ordinary coa-l burning furnaces into oil burners but it willbe evident that various features of the invention may be applied toother burnlo ers adapted for other uses.A

The apparatus includes meansfor initially forming a crude, over richcarbureted mixture of oil spray-suspended in and projected with arelatively small percentage of primary air, in combination with specialhomogenizing and propelling means whereby the spray in this initialdraft is atomized and intimately mixed with said initial air and alsowith some additional primary air and the whole projected asa homogeneousfuel draft in close relation to the main draft of tom and its innersurface cut off from the' air necessary for complete combustion. 'Ifhisfuel draft may be caused to burn according to my lnewly discoveredmethod described below; but various features of the homogeq nizing andpropelling means may be used in connection with fuel mixtures of primaryair with vapors or even gases derived from other sources or where thecombustion is not caused to develop according to the preferred form ofcarrying out the invention.

The/means for forming the initial spray and air draft is shown as beingof the centrifugal spra cup type. A. small electric motor is emp o ed torotate thecup at the speeds require for centrifugal operation andpreferably this same motor is utilized. fordriving my homogenizing-andpropellin means.,

n the preferred embodiment, the draft vmixture is propelled outward, in.a circular sheet, above a hearth that closes the greater part of thebottom of a furnace so that chimney suction or equivalent draft-inducindifference'of pressure is caused to take e fect through the air inletscontrolling the main supply of air for supporting complete' combustion,preferably this'main air'draft is through an annular inlet closelysurrounding theatomizer outlet and preferably the main air draft isdirected upward to inter-v sect the path of the initial air vand spraymixture.

An important feature of the invention is the attainment of practicallyperfect combustion without the use of excess air, yet

With ractically noiseless operation and freedom rom roaring which hasheretofore been an unavoidable accompaniment of eicient' combustion ofsprayed or atomized fuel oil. According to the preferred method, thecombustible mixture is projected outward from va central rotor with suchforce and under such conditions that the mixture will be ignited and theflame will begin around a circumference as remote as may be desired fromthe rotor, with the result that the flame l line may be'localizedadjacent the edge of the hearth where it oins the wall of the furnace orboiler', so that the flameline will be the lower edge of acontinuous'wall or cylinder` of flame conforming to and, as it were,clinging to the inner surfacesof the walls to be heated.

This cylinder of flame is closed at the botupper face of this layer doesnot ignite because its air content is too small and too uniformlydistributed. Hence instead of burning 4it becomes preheated ready for'the energetic combustion that follows impingement on the surrounding'walls.I Furthermore, the upper surface of this sheet entrains from abovesome oftheburned out air which is deficient in free oxygen and rich incarbon dioxide while the lower surface entrains fresh air. posite'sheetimpinges on the encircling walls, the impact and commingling ofconstituents results in a flame which is slow-burning and ofnon-explosive quality particularly onthe inner or exposed surface,whereas the` surface contacting with the boiler or furnace wall is muchbetter supplied with oxygen. Consequently, the exposed surface has noroaring tendency while the maximum heat When this comdevelopment isclose to the wall to 'be heated.

4The circular wall of flame which I produce in this way, thoughremarkably uni- `form, is likely under varying conditions of tate aroundthe axisof the burner alongthe rotor thatdischarges a relativelypowerful :blast alon' -lines more or less tangential to a circle w ichis of substantial diameter as Acompared with Ithe diameter of thefurnace or boiler.' The non-radial impingement of such a draft on theouter walls results in the above described slow rotary movement of dllthe flame.

'llhe :most important factor in obtaining .the above effects is thecombination with the primary air and spray projecting means, of asecondary or homogenizing propeller' or fan located'in-the path of therich mixture from said 'rimary means. This propeller is referab ydesigned and. operated soas to de ect, bao and homogenize the primaryair and oil mixture together iwith a substantial ladiniiiture ofadditional primary air,

while ensuring the desired high radial veloc? ity of the draft as awhole. By using fan blades having a forwardly wedging coin.n ponent, asin repellers, the blades may be arranged so tat they intercept andbreak' up all outwardly projected spray drops in the primary mixture,while at the saine time rgreatly accelerating the draft as a whole.

he thorough homogenizing thus accomplished makes it possible to mix inadditional primary air to a percentage much nearer that necessary forperfect.combustion than has been heretofore practically attainable. Thatis to say, in prior motor driven oil sprayers where the' repulsion ismainly hy centrifugal. force, t `e primary carbureted mixture may be asa whole very deficient-in air yet certain regions or spots contain mii:-tures where the air and oil are in approximately explosive condition sothat ignition occurs at such' points and 'thecoinbustioii line creeps inquite close to the burner, while relatively large drops of oil arethrown against the walls of the furnace or drop on the hearthunderconditions entirely unsuitable for perfect, efficient combustion; f

. The interference and yliomogenizing function of iny supplementalfanlisclearlyohs tinguishable -from its high velocity propellingfunction although these two functions are best served each incombination'with the other. j

- The lioinogenizerv referablyincludes two separate sets of bla esoperating in succession on the spray'.` Preferabl theyare concentric,-the inner set encirc in projector and, in turn encircled y the outerset. The thus present successively higher periphera speeds to theoutwardly travelingy 'sprayed mixture. Thesekblades are carried rby anannular. rim that projects horizontally the spray v trovare into thepath of upward draft from the an-` nular'air inlet, deliectingand-baling said draft where it intersects the path of the spray,thoroughly mixing part of it with the spray and, under most conditions;deliecting part ofit outwardly'so that the lower face of the outwardlytraveling draft adjacent .oil particles and homogenizing'thei'r mixturewith the air. Hence they are designed for `substantial interference andbaiing of the spray and draft.

While the blades will be of substantial ad? vantage if set radially, asin paddle wheels, l prefer to have them inclined to' the direction ofperipheral 'movement and also incline'd to the plane of rotationso thatthey have an inclinedfplane or wedge propelling effect as in a screwpropeller as well as the.,

centrifugal blower or..ypaddle,.,wheel effect. Preferably', the wedgepropellinv effect is upward and as the inner set ,oie blades is closedat the top bythe above described rim or wall at right angles to theaxis, the draftinoveinent in this direction is baed .producingcompression, deflection and eddy effects that contribute yto theatomizingy and homogenizing of the mixture. rllie outlet lades freelypropels f the draft outward side of the outer set org blades is notclosed in a circular sheet having its lower Surface overlying' andmerging into the purer air' which has been deflected along the uppersurface of the hearth.

l ani able to secure the .above homogenizing and propellingeffects withVa rotor say seven or eight inches in diameter driven at relatively lowspeed, say i700 or 1800 revolutions per minute. rllhese speeds areeconomical and are not destructive on the motor. @there have employedmotor speeds twice as great without attaining or even discovering'` thepossibility of. the above described features of oil burning according tomy invention.

Furthermore, when the device is installed and-'operating as abovedescribed, whereby the non-burning sheet extends entirely to the wallsof the furnace or boiler so that the upper face of'the non-burning sheetand the inner face of .the tlamecylinder are lentirely outY olf fromfreea ir,the diluent action of the products of combustion which ,filllthe interior of the furnace is so great that ltemperaturesfon the top ofthe'burner within Ythe furnace are'in many cases 400 and500 uless'thanin the .case off any rior l burners of this t e. `Furtherinoi'e,tetemperatures lbelow t e hearth in `the a'sltpit where the;

ico

` sheet extends upward to the crown sheet and into the flues where thefinal phases ofcomplete combustion are evidenced by t-he blue flamecharacteristic of hydrogen and carbon-monoxide combination.

It 1s to be understood, however, that the blast of draft mixture which Iam able to produce by means of my homogenizer includes vapor insuspension and is more like a gas than a mixture, and it may becontrolled to burn in various Ways. For instance, by cutting'down thestack draft and thereby reducing the air supply, the highly coloredllame may be made to entirely disappear, in which case the Whole body ofthe furnace Will appear to be filled With a slightly bluish or almostinvisible flame, indicating that my homogenized mixture has some of thequalities and may be used to produce effects similar to those attainableby manipulating the air supply of ordinary illuminating gas, and Iattain these results with ordinary fuel oil.

The above and other features and noveldetails of my invention will bemore fully understood from the following description in connection withthe accompanying drawings, in which Fig. 1 is a viewof one form of myburner and one form of installation and use thereof,

the burner and arts of the furnace inwh ich it is installed being shownin perspective Aand parts of the furnace'being broken away;

Fig. 2 is a vertical axial section through the burner and a portion ofthe hearth;

Fig. 3 is a vertical section on the line 3-3,

Fig. 4, showing a form of homogeni'zing.

mixer and propeller which is preferred for use in place of those shownin Figs. 1 and 2;

Fig. 4 is a plan View from below, Figd;

Fig. 5 is a vertical section like that of Fig. 2 but showing modifieddetails of construction Fig. 6 is a sectional detail on the line G-G,Fig. 5; and

Fig. 7 is a. sectional detail on the line 7-7, Fig. 2;

In Fig. l, I have shown a complete installation in accordance with mypresent invention, because as is evident from the for"- goingexplanation of the preferred operamember having an' upst-andmg defininga drainage groove 17 and affordtion, there is a .true combinationbetween the oil atomizer and projector ano the furnace in which it isinstalled, the latter being, ineffect the burner and the former beingnot really a burner but rather a carburetor for supplying the peripheryof the hearth with a peculiarly uniform, stratified, combustible. Asshown, the furnace is of conventional type, comprising an 'ash pitA,boiler walls B, combustion dome C, tlues l), l), communicating with thechimney, not shown, through pipe E, which may be controlled by thebutterfly damper F and air inlet Gr., Such a furnace may be ofconventional type, originally designed for coal burning,l but for mypurposes the gratehas been removed And `the combustion chamber H closedin at the bottom by hearth I of refractory material at the center ofwhich is the annular air inlet surrounding the rotary sp lay cupcarburetor K. x

The air draft is through collar 10, through which projects'shaft 11carrying homogenizing rotor12 having propeller blades 13v surroundingthe outlet from the centrifugal spray-cup 30,' which is alsoimounted onsaid shaft. i f

As shown more clearly in Figs. 2 and 5, there is an annular passage'between the spray cup and collar 10, not only for clearance to permitrotation of the former,

.'butalso to provide for thelmain air draft' that is drawn into thefurnace by chimney suction. i

The collar 10 is supported by a latform ange 16 ing asupport for thecircular plate 18 on which `rest theinner ends of the hearth blocks.Near the edge of the hearth, and

referably outwardly directed, is a gas pilot light burner a', which iskept continuously 'l burning by gas supplied from any suitable source.The weight of the hearth support 15, 16 is carried by leg sections 19telescoped in leg sections 20 and' adjustably held by screws 2l. Thereare preferably three legs to afford three-point support. v

As shown more clearly in Fig. 2, each leg sec-tion 20 has screw-threadedinto the lower end thereof, anadjustableextension 22 secured by lock nut23, whereby the legs may be readily adjusted to true vertical eventhough the floor of the ash pit be very uneven. The lower. end of eachmember 22 is ieo preferably headed as at 22. and the head is cushionedby a rubber block 24., held bv metal clip25 secured by central screw 26.Three-point support makes the adjusting operation easy.

Projecting through and concentric with the collar 10 is the :entrifugalor carbureting spray-cup 30, formed at the bottom with inlets 3l.fol-the primary air and carrying the'picker .tubes 3 2 for supplying theoil to viously the -cover member 39 may be .con-

sidcrcd as part of the cup 30. ln the form shown in Fig. 2 there is asecond cover member fitted on top of 39. Preferably these covers 39 and40 carry the baille annulus and the propeller blades described below. l`Disc 37 and cover plates 39 and 40 are clamped down on the top of thetubular cup memberl 34 by an annular clamping collar'41 secured by aclamping nut 42. All of the parts may* be suiiciently held againstrotation on the shaft 35'by the clamping action of nut 42, but I preferto provide a keyv44 engaging clamping collar 41 and extending. throughv40, 39 and /37 into 34, as shown.

The bottom of the cup 30 is 'thickened downwardly to provide an adequatelateral bearing for the picker 'tubes thatextend.

downwardly therethrough and are Secured therein in any desired positionof ,verticall adjustment by means -of screws 46. Also.

integral with the bottom ofthe cup Iand outside of the downwardlyextending icker ltubes is a circular depending lip .47 a apted to closethe opening into a suitable oil well casing 48. This casing ispreferably provided with a plurality of horizontal diaphragms, as 49 and50, which clear the rotary'closure 47 and' with itv form a labyrinthfacilitating downward drainage of oil intov the oil supply chamberorwell 51- and baf- {lingeseape of oil'from said chamber to the outside.The depending annulus '52 serves similarly to baiile' splash and dampswave motion that maybe set u bythe pickers when rapidly rotated tolli tthe oil. Rotation 'of the oil is damped by radial ribs 54 projectingfrom the bottom of the oil reservoir almost to the level of the normalsurface of the'oil.

The oil well has a cylindrical barrel 55 and the cup bearingshaft 11, 35hasta dow-n ward extension which is journaled on ball bearings in saidbarrel. For lubricating 4 purposes the top and bottom of the barrelbelow the lower` ball bearing and above the upper ball bearing areclosed by packing held in bushing 58 'screw-threaded therein, the lowerone being secured by lock nut 59.

The cavity is initially filled in with bearing grease and additionalgrease may be forced in at any time through duct 6()-qt by removingscrew plug 61 and applying a grease gunu Below the shaftv and inalignment theremore@ with is the electric motor 63, which may be ofordinary construction adapted to use alternating or direct current, anddesigned to rotate the spray cup, pickers and homogenizing propellerscarried thereby at the required speed which, as explained above, may

be as lowI as 1700 to 1800 revolutions per minute for a model, built ona scale which will make the extreme over-all diameter of the homogenizereight (8) inches.

The armature shaft of motor 63 is detachably secured to the spray cupshaft by a flexible coupling conventionally indicated as comprising twosimilar members 75, 75, each having driving lugs 76, engaging a block 77through'which the driving thrust is applied.

The oil well structure and motor are supported in any suitable way. Asshown in Fig. 2, the oil well has three-point support fromthe platformmember 15 by means ofl stud bolts 80 screw-threaded into 15 and passingthrough vertically k,apertured ears 81 which are integral withv andoutside of a drainage gutter 83 which is integral withl "theoil well.4Any desired positionof verti cal adjustment for. the oil welldrive shaftAand spray cup carriedtherebymay be xed by loclrn1`1t84, verticaldisplacement being prevented by thumb nut .85.` In the form lshown, 'themotor issecured by screws 90 adjustably engaging adepending bracket 91which is secured to the bottomv of the oil well -casing by ange 92fitting against the same and secured thereto by screws not shown.

by deep iianges'93, and 94.

Oil is supplied through the bottom of the oil well by pipe 95 and wasteoil from collecting gutter 83 is drained offthrough pipe 96 J Thevertical bracket'member -91 is stayed lIhe gutter 83 is in position tocollect oil i from the spray cup and also from the groove 17, whichdischarges through the duct '17,,

but its main .purpose is to lcollect oil that drains from the inclinedhearth when the pilotl light fails --or for any other reason vwhen oilis being discharged at a rate greatly in excess of the rate at which itis being burned. In such cases the oil drains down the incline of .thehearth and through the' slots 10t1 in collar 10 and drips into the col-`lecting gutter 83, whence it goes through ipe 96 to a suitable controlmechanism orming no pa'rt of my present invention.

i'It issuiicient to say that this mechanismaccurately controls the levelof the oil in the oil well and completely shutsof the supply of oilwhenever there is excess drainage through pipe 96.

The icker tubes are' preferably' of the shape siown in Fig. 7, thepicker at -the lower end consisting of a narrow integral extension 322Lformed by cutting away the tube, bending it horizontally throughsomething less than a quadrant of a circle andV I- cutting the end toV-shape, as at 321 so that it acts 4asa plow to throw aside the oil thatis not skimmed oli by the upper surface of the picker. The thin film ofoilis skimmed o by reason of the fact that the oil is stationary whilethe picker tip is traveling circularly at high linear speed around acircle which may be, say, six or'eight inches in circumference, drivenby a motor which is rotating, say, 1750'revolutions per minute.

Although the oil is mobile, it is held by.

. inertia against the thrust of the picker' and is deflected upwardthrough the tube at high velocity. .Air is also carried up in the sameway and the upward movement of both of them is facilitated by the factthat thetube is cut olf at an angle on the rear side as shown at 32C.The elect is-that since the speed of rotation of the? upper end of thetube is greater than that ofthe air within the spray cup, there is'asuction effect applied at the outlet.' In this connection, it is to beremembered that an even greater suction effect is applied'by reason ofthe fact that the cup itself is a centrifugal blower and tends to drawin air through tube 32 as well-as through the regular air inlet 31. Ob-

viously also the picker is itself an air scoopv as well as an oil scoop.

The amount of oil supply can be gauged withl greatest\\accuracy by'adjusting the vdepth ofoil in the oil well, and one advantage in havintherpicker cut away to a mere finger as s own; in lthe drawings, isthatthe amount of oil lifted will be 4more nearly-proportional to thedepth of the oil.

The amount of oil could lalso be v.varied by vertically'V adjusting thepicker tubes, but this isan undesirable way, since the oil level in thewell should be kept 'as near-the top of the ribs '54 asl is'practicable,thereby mak ing the ribs as efective' as possible 1n pre- `venting'A thepickers from imparting rotary desirmotion tothe' oil, it being obviouslthe oil able to minimize all disturbances o and hold it stationary asagainst the-scoop action of the pickers.

The spray thrown from theupp'er end of the picker tube is .subjected tocentrifugal,

force tending to drive it'throu h the air `currents within the-cup 30and 1n practice a much of its impinges on the side of the cup L adjacentthe outlet annulus. Much of it,

however, goes into suspension .in the primary' air, which is dischargedlthrough the same outlet by centrifugal force which is assisted by thefan blades 38, although the latter may be omitted if desired. The richlycarbuthe cover member39, and the adjacent bases l reted mixture isdischarged upwardly agalnst the horizontal bale annulus 100 of oftheinner propeller blades`13. The unsuspended oil creeps up the 'walls ofthe cup'l by centrifugal force and-fis projected. in

" have greater peri minute drops against the intermediate ortions ofseid blades. `This is on a leve below the primarily carbureted air andin the path of the main air draft coming up through thecollar 10 at anangle to the horizontally projected liquid. This tends todrive upwardthe minute 4drops that have been shattered by impact with the innerfaces of the blades 13, toward the baille 4plate 100 and those that havebeen caught by the outer surface of blades 13 upward toward thehorizontal or baille annulusl 101 of the outer propeller. As la resultof the baflling, eddying, mixing and shattering thus produced, a desiredamount' of additional primary air becomes incorporated in homogenizedmixture with a finely atomized liquid which is propelled outward. Alarge part of the upward maindraft, however, 1s

deflected art being driven outward by the' propeller lades as'an air'stratum merging such high outward velocity that if any particles of oilremain too heavy for suspension in the carbureted mixture they willnevertheless be carried alone toward' the peripheryof the hearth or, ifJany of them fall onA the' hearth, -as when the furnace is beitl startedup, they will be speedily evapora and swept to the'periphery of thehearth.

the up` The homogenizing propeller may be made in a variety of waysprovided 4the blades be formed with a view to propelling aswell asbathing and homogeniz'ing the draft. In-

Fig. 1, the blades are formed by radially and then bending these bladesdownward so slitting a circular disc to form narrow blades that theywill surround and extend belowy l the lip of the lcentrifugalcarburetercup and also twisting them so that they willl have the outward.wedging orpro elling effect in addition to the centrifuga effect.

and the bailiing effect. Even as shown in Fig.' 1, the lbladesubstantially encompasses the outlet of thecup so that when in rapidrotation, any drops from the -lip of the cup are interce ted andshattered. Even iao so, 'it mav be advisable to use an inner homoge Ienizer of similar construction but of less radius `and preferably .withblades *of greater pitch than the outer blades.- A s before' pointed out.the inner set of blades heral. speed than the lip of the cup and t eouter set of blades .has

:so a sufficient distanceto A permit passa e of all greater peripheralspeed than the inner set.

A rugged 4construction for the above purpose in which the blades arecombined with extensive baflie surfaces at angles between 45 and 90 tothepath of outwardly projected drops, 4is shown in Figs. 3 Vand 4.

Here the cover discs 39b and 40a have the horizontal bafllin'g surfaces100EL and 101a lset 4of blades has -a marginal rim v113",

which `increases the structural strength. of the anchorage for blades`1,13b and also serves as a guard to lessen danger from Contact with theperiphery'. of the device While it is rotating at'high speed.

In F1g. 2 the homogenizing propellors are shown as being scantilysupplied with propeller blades. Good results may be obtained by havingthe spaces between the blades in each set approximately equal to thewidths of the adjacent blades, particularly if the registry'is such thata blade 13'rt coincides with each space between vblades l13, but ingeneral it will be found that the close setting shown in Fig. 1 and eventhe non-propelling baille surfaces 113d in Figs.`3 and 4, will producebetter results. In all cases, however, much depends upon theproportions,

designs and pitch, angles of the blades as well as on theirI dist-anceapart and relations to each other.

A. somewhat different arrangement of homogenizing propeller isshcwn inFig. 5. Here the outer propeller Vcarried by the motorv shaft androtating at the same speed.- as the ,cup may be the'same 'as that shownin any of the figures above. described, but

in lieu of the inner ropellorl -IJnay arrange a stationar set of lades213, mounted on an upwar ly extending sleeve 248 spaced apart from theouter Wall of the cup 230 or a large .part offthe main ,air supp y.y4.The stationary blades 213.l1atf the upper.. Y'edge thereof areinclined loutward-ly and are also twisted about their longitudinal axes'so that they furnish inclined surfaces deflecting the spray from the cu'p outlet annulus upwardly and circumferentially forward in the direc---tion of rotation of the cup. This causes deec- L tion of the draftmixture and also the main airisupply toward the rear faces of therotating blades 13, but the stationary blades may be more nearly radialandrmay even be inclined in the o posite direction so as to tend t0baillev the raft in a direction contrary to the direction of rotation ofthe blades 13. In the preferred arrangement, the.

blades 213 tend strongly to deflect the drops from the draft upwardtoward the baille surface 101.

As the stationary blades have no rotary` mot-ion tendingto throw ofi'the oil by centrifugal force, I may provide the outside of the cup withhelical propeller blades 228 designed to powerfully accelerate the mainair draft in its upward movement so that it will be effective in itstendency to strip the oil upward off of the upper ends of the blades213. A

The enclosing of the main air draft by the cylindrical wall 248 makes itpossible to closely control the amount of air in this draft by means ofa rotary damper 250 (see Fig. 6) controlled by an operating handle 350projecting outward beyond the leg supports of the device.

his figure also differs from the others in that the Aspray cup 230 isflared outward more nearly in parallelism with the natural trajectory of`the spray and ainthrown from the outlet ends of the tubes 32, Ithusallowing more o-f the oil to be carried through the outlet annuluswithout impingemen't on the Walls of the cup. Moreover, such drops as doimpinge on the walls will be cleared therefrom more rapidly by reason ofthe more favorable angle of impingement and also because of the muchgreater effect of centrifugal force duel to lthe wide angle of the mouthof the cup. In this Fig. 5 the motor and other rotating parts arecarried by 'adjustablestud bolts 80, very much as in Fig. 2, but thedrip trough 285 is on a lower level and more accessible. It is inposition not only to receive drip from the hearth, but also fromY anopening at 290 in the side ofthe oil well. This opening is well aboveany level the .pickers are intended to work at and 'will only `come intooperation in case the oil well' is flooded.

A further feature is having the baffles for reventing rotation of theoil not only along the bottom of the oil'well as at 254, but also aroundthe sides of the well as at 354.

As explainedl above, my 4invention is not limited to the details ofconstruction above described, nor is it limitedto the preferred methodof use. Any of the homogenizer constructions shown in the other figuresmay be used in combination with the carbureting cup and air supply meansshown in Fig. 5,

and with any of the forms it ispossible to adjust the amount of air andoil and` the proportions of air and oil and the outward velocit-ies withwhich theyfare propelled, so that the homogenized fuel sheet or layerwill be non-burning until it reaches th'e periphery of the hearthy andwill there burn in a wall lof flame clinginglto the walls of the furnaceand extending into the flues. This .CFI

flame lmay be varied from a comparatively thin layer of dense yellowflame until the inner surface' becomes more indefnite'and more blue andthe blue can be made to shade out towards the center until the entirefur- .nace cavity is filled with a bluish almost invisible flame in lieuof the highly colored y definite flame. l

As will be understood from the foregoing, a very important feature of myinvention is having the central centrifugal spray cup spraying the fueloil in a narrow zone about the periphery of the hearth, at the base ofthe upright Walls tol be heated thereby, in

rectly coupled -to the spraycup, althoughV such mannen that the flameline is localized 1n said zone along said base and is prevented fromcreeping inward toward the central spray cup. lThe various contributingfactors are in the aggregate so effective, that an or.-

di-nary commercial type motor turning 17 OO.

to. 1800 vrevolutions per minute can be disimilar results may beachieved by the superspeed specially built motors'now-commonly used forsuch purposes.

An important factor tending to ensure this' locatlon of the flame lineis thehomogenizing,

* and projecting with the spray of a relatively large volume of primaryair propelled outward with and at approximately the same Ivelocity asthe spray, thus serving the double a better fuel draft p ur o se ofproducing f whi e at the same time adding greatly to the volume, weightand ycarrying powervthat is practically effective in'carry-mg the fuel.

the hearth, at the base ofthe upright. walls,

instead of near the'sprayvv cup. The initial-l combustion zone is 'thusremote from the intermediate surfaces of the hearth between the cup andthe peripheral walls. Thus their lnitially cold lsurfaces remain colduntil the entire combustion process above described is in fullo eration,and thereafter they are protected rom being heated to combustionpromoting temperature by theheat absorbvIng action of the unignitedspray and air Continuously projected from the center out-y lward abovesaid hearth surfaces.

I' have found in certain cases, however',

that if for any reason the flame line 'does break back to lt-hehomogenizer, it will con- Y tinue there until the apparatus is stoppedund restartedagain. Hence in stopping and l, restarting, it is highly imortant tohave A,the motor reach full spee before turning vto promote lcracking of theheav creasing the speed of the motor.

rWhile there are various ways' of ensuring ignition at a oi'nt remote'from thefyspray cup, I prefert e arrangement shown Iin Fig. 2, where thepilot light is shown as'projecton` the oiland to turn off' the oilbefore ing its jet outward but at 'an angle lnclined towardstheobserve'r, which, as will be noted, is substantially parallel. withthe direction of spray and draft tangentially pro- 'ected from the s raycup and homogenizer referabl ,this ]et is directed against the --surfaceo a cast iron member w', which is lkept hot by the continuously lightedpilot light impingingthereon atv all times, regardless of whether theburner is or is not operrating. Homogenized gases sweeping lengthwisealong the flame of this pilot light may be ignited, particularly betweenit and the surfaces of thereby augmenting the effectof 'the that may fal upon said surface and promotpilot flame in igniting Aoil spray ingcircumferential progress of combustion around the periphery of thehearth.

'The cast iron surface itself when hot tends hydrocarbons to producecombustible met ane and `oxidation of carbon to produce carbon monoxide,but, if desired, the cast iron surface ma be covered with refractorymaterials, inc uding oxides or carbonates of well known catalyticmetals.

curves into the upright surfaces of the furnace may be of similarrefractory materials or may' be of ordinary fire clay.

The lagging` around the edge of the hearth where it- These refinementsare not essential, howfever,.b ecause, when in full operation', merelmplngement and deflection of my vcomposite draft causes very hlghtemperatures,

say 1800 F. or more, in the 'annular' zone of the corner between theperiphery of the hearth and base of 4the furnace walls. Undoubtedly thisintense heat evolution islargely the' result of incomplete combustion orexothermic .reaction yielding carbon monoxidey land lmethane fuel gasesalong with some superheated steam and-carbondioxide products of somecomplete'combustion that also occurs in-this zone. completecombustion islocalized adjacent the hot furnace surfaces where the purer airProbablyv also the naturally' flowswhilev the oil cracking and fuel'-gas reactionsy are" mainly in the inpresented layers where there isonly enoug oxygen for the exothermicreactions and wherediluent productsof combustion entrained .from within the furnace serve to slowdown theox1d1z1ng processes.

Whatever vmay be the*` .precise details of' working out vofthesereactions, the characteristic effect attained in full operati-onissudden very high temperature in this narrow zone at' the basev of thewalls resulting in the production of sufficient fuel gas 'to completethe breaking down of all the fuel Constituents of the draft and withdecreasing temperatures as the slow bright flame flows up the walls ofthe furnace, until at the upper part and`in the fiues there is only thedark or blue flame characteristic of complete combustion of fuel gas.`When the furnace has been brought to high temperature by this method,the air may be cut down until the combustion is nearly or entirelytwo-stage, i. e., exothermic reaction or partial oxidation producingfuel gases followed by slow complete combustion of said gases, evidencedby great decrease'or even complete disappearance of the bright llamesheet and diffusing of dark or blue flame combustion from the wallstoward the center of the furnace. Intermediate conditions are easilyproduced -by simple changes o f the proportions and quantities lof oiland air. f

T he furnace, particularly the hearth, is an important factor, as willbe evident from` `the fact that a burner cup provided with thehomogenizer shown in Figs. 3 and 4, when operated in the open airwithout any hearth, will be found to'deflect, and downf wardly projectthe main body of the air draft at an angle of approximately Of course,no such thing happens in practice, because the hearth serves to supportand guide the draft that sweeps its surface.

I claim:

l. Oil burning apparatus for use in a furnace having a combustionchamber with a stack gas outlet and a hearth with a cen-` tral. openingclosingthe lower end of said chamber, said 'apparatus including a mixingand projecting device in the opening in the hearth spaced therefrom toprovide l an annular inlet for a main draft of air ensaid hearth to amain draft o tering the combustion chamber, and comprising rotary meanshaving a `rotor element to draw up oil and air therethrough,

within the main draft annulus, and mix the same to produce a richmixture; and to pro-v ject 1t laterally between .the products of com-lbustion in the combustion chamber and the main air draft, said rotorelement including a. deflector element above the path of saidrich'inixture adapted to force the main. air draft outwardly above thehearth, said fuel. draft entraining products of combustion at itsuppersurface and air at its lower surace. i

2'. Oil burning apparatus for use in a furnace having a combustionchamber with aA vstack gas outlet and a hearth with ,a central openingclosing the lower end of said chamber, said apparatus including a mixingand projecting device arranged in the opening, and spaced from the inneredge .of provide an annular` inlet for air entering the combustionchamber, and comprising means, including a rotary element having outletmeans at its periphery,

to draw up oil and air and mix the same to produce a rich mixture and tomixture through said outlet project th-e j the products of combustion 1nmeans between ,the combustion chamber and the main draft stack gasoutlet and a hearth with a central opening closing the lower end of saidchamber, said apparatus including a mixing and projecting device in theopening in the hearth spaced therefrom to provide an annular inlet for amain draft of air around the mixing and projecting device, andcomprising a rotary element to draw up oil and air and mix the same toproduce a rich mixture vand to project said mixture laterally betweenthe tion in the combustion c amber and the main air draft, and todeflect the main air draft outwardly above the hearth soV that the fueldraft strikes the upper portion of the main air draft, thus entrainingproducts of combustion at its upper surface and air at its lowersurface.

4. In an oil burning apparatus, means for projecting a fuel draft of oiland air in combustible `relation to the air supply required-for completecombustion, including a centrifugal carbureting cup, means for rotatingsaid cup at high speed to atomize and project oil and primary air in anannularly spreading layer constituting the fuel draft and means fordirecting the main air supply in an annulus surrounding said cup and ina direction for intersecting the path of the annular' layer constitutingthe fuel draft, an annular deflector carried by the carbureting cupabove the fuel draft, and inner and outer sets of propeller bladescarried by said deflector and radially surrounding the annular outlet4thereof-to interroducts of combusi les cept, homogenize and propel thedraft mixcombustible relation to the air supply required for completecombustion, including' a centrifugal carburetin cup, means for rotatingsaid cup at hig speed to atomize and project oil and primary air in anannularly spreading layer lconstituting the fuel draft, means fordirecting'the main air vsup ly in an annulus surrounding said cup an ina direction for intersecting the pat tends to minglewith the annularlyspreading fuel supply and all portions of the mainair supply aredeflected towardI parallelism with said fuel draft.

6. In an oil burning apparatus, means for projecting a fuel draft ofoilland air in combustible relation to the air draft required forcomplete combustion, including a centrifugal carbureting cup, means forrotating said cup at high speed toV atomize and project oil and primaryair `in an annularly spreading layer constituting the fuel draft, meansfor directing the mainair draft in an -annulus surrounding said cup andinA a direction for intersecting the path of the annular layerconstituting the fuel draft at an angle greater than forty-five degrees,an annular dellector carried by said cup arranged abo-ve the fuel draftor mixture of oil and primar air to deflect said main air draft wherey-thc'inner portion of the main air draft tends to mingle with theannularly spreading fuel draft and all portions of the mam air draft aredeflected toward parallelism with said fuel draft, said deflector beingof much greater diameter than the fuel cup and having at its margin adownwardly directed flange lmember adapted to intercept the path of thecentrifugally projected fuel draft from the carbureting cup and tobaffle both thefuel draft and the portion of the main air draftimpinging thereon.

7. In an oil burning apparatus, means for projecting a fuel draft of oiland air in -combustible relation to the air draft required for completecombustion, including a centrifugal carbureting cup, means for rotatingsaid cup at high speed to atomize and project oil and primary air in anannularly Spreading layer constituting the fuel draft, means fordirecting the main air draft in an annulus surrounding said cup and in adirection for intersecting the path of the anynularfuel draft at anangle greater than forty-five degrees, an annular dcflector carried bysaid cup arranged above the fuel draft or mixture of oil and primaryai'r to deect said main air draft whereby the inner portion of the mainair draft tends to mingle with the annularly spreading fuel draft andall portions of the main air draft. vare deflected toward parallelismwith said4 fuel draft, said deflector being of much .greater diameterthan; the fuelcup and having at its margin a downwardly 'directed flangemember adapted `to intercept the path of the centrifugally projectedfuel draft from the carbureting cup and to baille both the fuel draftand theA ortion of Ithe main I air draft impinging. t ereon and havingopenings through which the -deflected air and the baffled mixture mayescape radially.

8. In an oil burning apparatus, means for projecting a fuel draft of oiland air in combustible ,relation to the air draft rcquiredv for completecombustion, including a centrifugal carbureting cu means for rotatingsaid cu at high spee to atomize and project oil andl spreading layerconstituting the fuel draft,

primary air in an annular-ly means for directing the main air draft inan annulusI surrounding said cup and in a direction for intersecting thepath ef the annular fuel -draft at an angle greater than forty-fivedegrees, an annular deflector car,`

ried by said cup arranged above the fuel draft or mixture of oil andprimary air to deflect said main air draft whereby the inner portion ofthe main air draft tends to mingle with the annularly'spreading fueldraft and all portions of the main air draft are deflected .towardparallelism with said fuel draft, said dellector being of much greaterdiameter than the fuel cup and having at its margin a downwardlydirected flargc member adapted to intercept the path of thecentrifugally projected fuel draft from the carbureting cup and tobaffle both the fuel draft and the portion of the main air draftimpinging thereon and having openings through` which the deflected airand the baffled mixture may escape radially, said margin being formedwith propeller blades radially intercepting, baflling and ropellingoutward the portion of the dra t mix'- ture impinging thereon. i

9. In an oil burning apparatus, means ,for projecting oil and air incombustible relation, including a centrifugal spray means and means forrotating said first means at high speed to project theoil in an annularspreadmg layer of spray, in combination with a set of propeller bladesand means for supporting the same in fixed relation with.

the centrifugal spray means but located radiall youtside of such spraymeans and extendmg across the plane of said annular l layer ofspray.

10. In an oil burning apparatus means for radially projecting oil an airin comlmstible, relation, including a centrifugal sprayv intercept,homogenize and propel the draft mixture impinging thereon.

11. In an oil burning apparatus, means for projectingl oil and a1r incombustible reprojecting an annularlypspreading oil spra draf t,'` andaudriving motor rotating said and means for directing an u ward dra t.,blades.

of air across the path of the projected spray, Signed at New York inthe' conntyv 'of 10 a series of outwardly acting fan blades in an NewYork and State of New York this 31st i 5 yannulus spaced from andencircling said oil day of July, A. D. 1925.

A projecting means and extending across the path of the projected Aoiland intothe air f' -VFORREST A.

